df['Flag'] = ["High Bracket" if x > 70 else "Low Bracket" for x in df['prevsalary']]
df['Flag2'] = ["Increase" if x > y else "Decrease" for (x,y) in zip(df['nextsalary'],df['prevsalary'])]
df['col2'] = [int(x) for x in df['col1']]
mat = [[1,2], [3,4], [5,6]]
[x for row in mat for x in row if x%2==1]